The outlet box of this invention is an improvement upon the outlet box disclosed in my prior U.S. Pat. No. 3,728,470 issued Apr. 17, 1973. The outlet box disclosed in my U.S. Pat. No. 3,728,470 is formed from extruded metal stock and includes a bottom wall, a pair of side walls, and a mounting flange projecting outwardly from one of the side walls by which the outlet box is attached to a wall stud. When the wall stud is of wood or other rigid material, the outlet box may be attached to the wall stud by locating the box with one of its side walls juxtaposed to the stud and with the mounting flange overlying the stud, and by passing fasteners through the mounting flange into the stud. As long as the stud to which the outlet box is attached is rigid, the outlet box will not move under the normal pressure applied by an electrician in wiring the box. In present day buildings, the use of dry wall construction which includes the use of metal studs made of light gauge metal is common practice particularly where fire protection is required. When an outlet box is fastened to the light gauge metal stud, if not properly supported by some type backup support, it may move when pressure is applied by pressing an electrical attachment plug into a receptacle or from the pressure of operating a switch. Therefore some sort of backup support is required to keep the box from moving out of place. There are several methods in use by which electricians provide backup support for an electrical outlet box which is secured to a light gauge metal stud. One method is to fill the space between the back of the outlet box and the sheet rock wall panel behind the box with a block. This method is time consuming and costly. Sometimes the block used falls out of place.
Another method is disclosed in U.S. Pat. No. 3,767,151 issued to Glendon E. Seal and Willis R. Arford, on Oct. 23, 1973 and entitled Electric Wiring Box Positioner. The method disclosed by Seal and Arford includes the use of a bracket which has a straight portion having an open hook at one end and a perpendicular flange at its other end. The hook portion of the bracket is hooked over the open front edge of the side of the outlet box opposite the supporting wall stud so that the straight portion of the bracket extends rearwardly alongside the outlet box and engages the sheet rock wall panel behind the box. The bracket thus gives backup support to the outlet box on the side of the box which is opposite to the supporting metal stud. The bracket disclosed in U.S. Pat. No. 3,767,151 is of a fixed length, therefore the bracket must be of the correct length when it is applied to the outlet box to reach the sheet rock panel behind the box. This may be a disadvantage when an electrician is working on different jobs which may require brackets of different lengths. The electrician may thus be required to stock brackets of several different sizes.
It is also known to mount an outlet box in an opening in a hollow wall comprised of spaced front and rear wall panels without the use of any screw fasteners. One means to accomplish this is shown in U.S. Pat. No. 2,512,188 issued to William H. Wait and Will C. Jordan on June 20, 1950. Wait and Jordan attach a pair of outwardly projecting flanges to opposite sides of an outlet box and secure a spreader clamp in the central knockout opening in the bottom of the box. The outlet box is positioned in an opening in the front wall panel with the flanges on the opposite sides of the box engaged against the backside of the front wall panel. The spreader clamp is then adjusted outwardly of the box bottom by means of a screw toward the rear wall panel until a foot piece engages the rear wall panel. Continued outward adjustment of the spreader clamp then forces the flanges of the outlet box firmly against the back side of the front wall panel and thus secures the box in the wall opening without the use of screw fasteners.